[FFmpeg-devel] [PATCH v1 1/2] fftools: add global option to dump filter graph to stderr

[lance.lmwang at gmail.com]

From: Limin Wang <lance.lmwang at gmail.com>

It's useful for debugging filter graph purposes, now only lavfi can do that.

Signed-off-by: Limin Wang <lance.lmwang at gmail.com>
---
 doc/ffmpeg.texi         | 4 ++++
 fftools/ffmpeg.h        | 1 +
 fftools/ffmpeg_filter.c | 7 +++++++
 fftools/ffmpeg_opt.c    | 3 +++
 4 files changed, 15 insertions(+)

diff --git a/doc/ffmpeg.texi b/doc/ffmpeg.texi
index 9cccc2337d..7e55f67898 100644
--- a/doc/ffmpeg.texi
+++ b/doc/ffmpeg.texi
@@ -668,6 +668,10 @@ Defines how many threads are used to process a filter pipeline. Each pipeline
 will produce a thread pool with this many threads available for parallel processing.
 The default is the number of available CPUs.
 
+ at item -filter_dumpgraph (@emph{global})
+Dump filter graph to stderr. It is off by default, the option is mostly useful
+for debugging filter graph purposes
+
 @item -pre[:@var{stream_specifier}] @var{preset_name} (@emph{output,per-stream})
 Specify the preset for matching stream(s).
 
diff --git a/fftools/ffmpeg.h b/fftools/ffmpeg.h
index 7b6f802082..b3133e7e99 100644
--- a/fftools/ffmpeg.h
+++ b/fftools/ffmpeg.h
@@ -608,6 +608,7 @@ extern float max_error_rate;
 extern char *videotoolbox_pixfmt;
 
 extern int filter_nbthreads;
+extern int filter_dumpgraph;
 extern int filter_complex_nbthreads;
 extern int vstats_version;
 
diff --git a/fftools/ffmpeg_filter.c b/fftools/ffmpeg_filter.c
index 72838de1e2..35ba3a38db 100644
--- a/fftools/ffmpeg_filter.c
+++ b/fftools/ffmpeg_filter.c
@@ -1109,6 +1109,13 @@ int configure_filtergraph(FilterGraph *fg)
     if ((ret = avfilter_graph_config(fg->graph, NULL)) < 0)
         goto fail;
 
+    if (filter_dumpgraph) {
+        char *dump = avfilter_graph_dump(fg->graph, NULL);
+        fputs(dump, stderr);
+        fflush(stderr);
+        av_free(dump);
+    }
+
     /* limit the lists of allowed formats to the ones selected, to
      * make sure they stay the same if the filtergraph is reconfigured later */
     for (i = 0; i < fg->nb_outputs; i++) {
diff --git a/fftools/ffmpeg_opt.c b/fftools/ffmpeg_opt.c
index 71063cc443..44eb890e86 100644
--- a/fftools/ffmpeg_opt.c
+++ b/fftools/ffmpeg_opt.c
@@ -110,6 +110,7 @@ int frame_bits_per_raw_sample = 0;
 float max_error_rate  = 2.0/3;
 int filter_nbthreads = 0;
 int filter_complex_nbthreads = 0;
+int filter_dumpgraph = 0;
 int vstats_version = 2;
 
 
@@ -3523,6 +3524,8 @@ const OptionDef options[] = {
         "create a complex filtergraph", "graph_description" },
     { "filter_complex_threads", HAS_ARG | OPT_INT,                   { &filter_complex_nbthreads },
         "number of threads for -filter_complex" },
+    { "filter_dumpgraph", OPT_BOOL,                                  { &filter_dumpgraph },
+        "dump filter graph to stderr" },
     { "lavfi",          HAS_ARG | OPT_EXPERT,                        { .func_arg = opt_filter_complex },
         "create a complex filtergraph", "graph_description" },
     { "filter_complex_script", HAS_ARG | OPT_EXPERT,                 { .func_arg = opt_filter_complex_script },
-- 
2.21.0